chore: update docs and makefile (#83)

Makefile

@@ -2,47 +2,72 @@
 
 export PATH := $(abspath bin/):${PATH}
 
-# Dependency versions
-GOLANGCI_VERSION = 1.53.3
-LICENSEI_VERSION = 0.8.0
+##@ General
+
+# Targets commented with ## will be visible in "make help" info.
+# Comments marked with ##@ will be used as categories for a group of targets.
+
+.PHONY: help
+default: help
+help: ## Display this help
+	@awk 'BEGIN {FS = ":.*##"; printf "\nUsage:\n  make \033[36m<target>\033[0m\n"} /^[a-zA-Z_0-9-]+:.*?##/ { printf "  \033[36m%-15s\033[0m %s\n", $$1, $$2 } /^##@/ { printf "\n\033[1m%s\033[0m\n", substr($$0, 5) } ' $(MAKEFILE_LIST)
+
+##@ Build
 
 .PHONY: build
 build: ## Build binary
 	@mkdir -p build
 	go build -race -o build/
 
+##@ Checks
+
+.PHONY: check
+check: lint test ## Run lint checks and tests
+
+.PHONY: test
+test: ## Run tests
+	go test -race -v ./...
+
 .PHONY: lint
 lint: lint-go lint-yaml #lint-docker
 lint: ## Run linters
 
 .PHONY: lint-go
 lint-go:
-	golangci-lint run $(if ${CI},--out-format github-actions,)
-
-#.PHONY: lint-docker
-#lint-docker:
-#	hadolint Dockerfile
+	$(GOLANGCI_LINT_BIN) run $(if ${CI},--out-format github-actions,)
 
 .PHONY: lint-yaml
 lint-yaml:
 	yamllint $(if ${CI},-f github,) --no-warnings .
 
+.PHONY: license-check
+license-check: ## Run license check
+	$(LICENSEI_BIN) check
+	$(LICENSEI_BIN) header
+
 .PHONY: fmt
 fmt: ## Format code
-	golangci-lint run --fix
+	$(GOLANGCI_LINT_BIN) run --fix
 
-.PHONY: test
-test: ## Run tests
-	go test -race -v ./...
-
-.PHONY: license-check
-license-check: ## Run license check
-	licensei check
-	licensei header
+##@ Dependencies
 
 deps: bin/golangci-lint bin/licensei
 deps: ## Install dependencies
 
+# Dependency versions
+GOLANGCI_VERSION = 1.53.3
+LICENSEI_VERSION = 0.8.0
+
+# Dependency binaries
+GOLANGCI_LINT_BIN := golangci-lint
+LICENSEI_BIN := licensei
+
+# If we have "bin" dir, use those binaries instead
+ifneq ($(wildcard ./bin/.),)
+	GOLANGCI_LINT_BIN := bin/$(GOLANGCI_LINT_BIN)
+	LICENSEI_BIN := bin/$(LICENSEI_BIN)
+endif
+
 bin/golangci-lint:
 	@mkdir -p bin
 	curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | bash -s -- v${GOLANGCI_VERSION}